GREENSBORO--- For the second day in a row, North Carolina found itself playing catch-up in Saturday's Atlantic Coast Conference Tournament semifinal matchup with Clemson.

And once again, the Tar Heels found it within themselves to rally and win.

Behind a record-breaking 40 point performance by wunderkind Harrison Barnes, UNC overcame the Tigers for a 92-87 triumph that moves the Tar Heels into Sunday's championship game.

"It's an unbelievable game again," said UNC head coach Roy Williams immediately afterwards.

Barnes' 40 points were the most ever by a freshman in an ACC Tournament game, and the most scored in any single game by any ACC player this season.

He nailed six three-pointers in the game, shot 12-of-17 from the floor in total, and scored a whopping 14 points in overtime alone.

"I tried to fill in for what the team needs," Barnes said humbly. "Today we had a lack of production on the offensive end and I tried to make up for that."

Early on North Carolina had a great deal of trouble finding shots against Clemson's stifling man-to-man defense.

The Tigers, fired up coming off its 23-point blowout of Boston College on Friday that likely guaranteed an NCAA Tournament bid, came out and punched the top-seeded Tar Heels in the gut early in the game.

The Clemson guards shut down Kendall Marshall's passing lanes and helped slow down the talented UNC freshman on its way to building early leads of 14-3, 18-8, and 20-8 over the opening ten minutes.

"I have no idea why we got off to such a slow start," said Williams. "If I knew what the heck it was I already would have changed it. Recently we've been playing well early, but yesterday and today we didn't play as well early."

On its way to 12 made three-pointers for the game, Clemson controlled the tempo and decisively outplayed Carolina in the first half on its way to a 38-28 halftime cushion.

"Clemson did well," said Williams. "They had a tremendous effect on us. They were more aggressive. They had more points on second shots. They had more fast break points. They had more rebounds at the half, 19 to 11. They scored nine points off our turnovers."

"They had seven fast break points and we had none," Williams added. "All those are aggressive stats."

It was almost as if the Tar Heels had rewound itself from the Miami game and decided to play exactly the same way over the opening 20 minutes---listless, passionless, and generally sloppy.

One play that was really indicative of Carolina's rough early start was a missed free throw by Clemson in which John Henson misplayed it and allowed the ball to bounce out of bounds to the Tigers, who subsequently scored again.

The one bright spot for Carolina early in the game was Barnes, who scored 14 of UNC's first 20 points, and 16 of the team's 28 total points in the first half.

Without Barnes there's little doubt that Sunday's championship game wouldn't have been an option for the Tar Heels.

Trailing by 10 at halftime, UNC came out and seized the initiative in the second half, as they slowly pushed closer to the Tigers over the next several minutes.

Carolina took its first lead around the 10:45 mark, as Dexter Strickland fed Tyler Zeller in the post for a lay-in and a 53-52 Tar Heel advantage.

It gave the pro-UNC crowd assembled in the Greensboro Coliseum reason to finally get up and get loud after being quiet for most of the game to that point.

But Clemson showed why they're a dangerous team that could be major trouble for whoever they meet next week in the Big Dance.

Taking advantage of a temporary softening on the UNC defensive pressure, Clemson promptly went on an 11-3 run---climaxed by a three-point play by Stitt, who led Clemson with 25 points---to give the Tigers a 63-55 advantage with 9:10 to go.

Coach Williams called a timeout at 5:55 mark with Carolina trailing 69-64---a move similar to the one he made in the Miami game yesterday.

Whatever Williams said to his team worked on the defensive end, as Clemson only made one more field goal and one free throw for the remainder of regulation.

After Clemson scored those four points, making the score 73-66, UNC outscored the Tigers 7-0 over the next four minutes.

"In the second half we got more aggressive," said Williams. "Our defense got better."

Although UNC had a series of three bad possessions in the final five minutes---including a turnover by Henson, a poor shot by Zeller and a missed three-pointer by Marshall---the Tar Heel defense kept them in it down the stretch.

After Henson made a lay-in, Barnes nailed a three-pointer with a man in his face to cut the score to 73-71 at the 1:22 mark.

"Harrison started making a bunch of shots," said Williams in perhaps the biggest understatement of the weekend.

Following Barnes' conversion to cut the Clemson lead to two, the Tigers failed to score on its end, and with just 30 seconds left Zeller converted a jump hook along the right baseline to tie the game and force the extra session with the game knotted at 73.

After blowing its lead and failing to hold on in regulation one could get the sense that Clemson was in big trouble, and that's exactly how things went down in overtime.

Barnes and Marshall quickly nailed three-pointers, making the score 79-73 and forcing a Clemson timeout, and then Barnes scored again while getting fouled in what turned out to be the dagger for the Tigers.

Just for good measure, Barnes sank one more three-ball---his sixth of the afternoon---to make the score 86-77 with less than three minutes to play.

To its credit Clemson continued to fight---showing why they're a tournament team.

After managing to pull within three points in the final 10 seconds at 90-87, the Tar Heels successfully salted away the game at the free throw line, as Barnes finished his incredible game with a pair of charity shots to finish up with his 40 points.

"For him (Barnes) to get 40 points, a freshman ACC Tournament record, and for North Carolina guys---Lennie Rosenbluth, whose jersey is in the rafters retired, and Charlie Scott, whose jersey is in the rafters---Harrison's in big-time company."

In final summation of Saturday's game, one could say that the general theme of the ACC Tournament for UNC so far this year is that while they've struggled mightily at times, they've been extremely good when they've had to be.

And now its on to Sunday, where the Tar Heels will play for its first ACC title since 2008 and perhaps even a chance at earning a No. 1 seed in the Big One.